Ignition magneto



Nov; 24, 1925. 1,563,138

F. w. ANDREW IGNITION MAGNETO Original- Filed Oct. 5, 1921 2 Sheets-Sheet 1 P-Ku /6 INVENTOR BY Z M ATTORNEY Nov. 24, 1925- F. W. ANDREW IGNITION MAGNETO A 2 Sheets-Sheet 2 Original Filed Oct. 5, 1921 INVENTOR ATTORNEY Patented Nov. 24, 1925.

UNITED STATES 1,563,138 PATENT OFFICE.

FREDERICK VI. ANDREW, OF GLEN HEAD, NET/V YORK, ASSIGNOR TO EISEMANN MAGNETO CORPORATION, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

Original application filed October 3, 1921, Serial No. 504,934. Divided and this application filed April 1 7) all whom it may concern:

Be it known that I, FREDERICK TV. AN- oncuga citizen of the United States, and a resident of Glen Head, Long Island, county of Nassau, and State of New York, have invented certain new and useful Iniprovements in ignition Magnetos, of which the following is a speclfication.

My invention relates to that type of magnetos which are adapted to produce electric sparks suflicient to ignite the explosive mixture in the cylinder or cylindersof internal combustion eno-ines, more commonly called gas engines. The magneto of my inventioii differs in several material respects from the magnetos heretofore constructed and possesses advantages not inherent in prior devices.

One of the principal objects of my invention to const"'ict a magneto powerful enough to fire large gas engines and yet sutliciently small and compact to permit of installation in places where but little space is available.

More specifically considered, the features of my invention relate to a new and improved armature BGlSilLlCiBlOD and currentcolleeting mechanism for magnetos, the advantages of whic" w ll become apparent as the specification proceeds.

in the accompanying drawings,

Fig. 1 is a longitudinal cross-section of an ignition magneto constructed in accordance with my invention;

Fig. 2 is a plan view approximately on line 22 of Fig. 1;

Fig. 3 is a sectional plan view takenapproximately on line 33 of Fig. 1

Fig. 4 is transverse C1OSSSQC1J1011 of the drive end of the magneto, approximately on line '-i-f; f F g. 1;

Fig. 5 is a fragmentary perspective view showing my new primary brush construction,- this view being enlarged for the sake of clearness; and

Fig. (3 is a detached perspective view of the low-tension collector ring mounted on one of the armature end plates.

The main supporting framework of my new magneto preferably consists of a single casting of non-magnetic material, such as aluminun'i. This non-magnetic casting, indicated as a whole by C, comprises, in the main, a base 1, a pair of end plates Serial No. 705,461.

or pieces 2 and 3, and a top 4. Between theend plates the casting has rectangular openings 5 angle, in which are secured the iron pole pieces 7 and 8, as best shown in Fig. 4. opening 9 suliiciently large to permit insertion of the armature as a Whole, as may be seen from Fig. 3. The base 1 of the casting is formed with a recess 10 and the top l: has a similar recess or cutaway portion 11 for the purpose of accommodating the cylindrical armature, as will be understood. The end plate 2 has a central opening 12, through which projects the drive end of the arn'iature shaft, as will be explained later, and is further provided With aninwardly extending cylindrical flange or shoulder 13, as shown in Figs. 1 and 3. Between the end pieces 2 and 3 the casting is formed with a recess 14 to receive the legs of the permanent magnet or magnets M. The other structural details of the main casting or framework C will be referred to as the description of the drawings progresse's.

Between the pole pieces 7 and 8 is mounted a rotary or oscillatory armature, inclica-ted as a whole by A, which has the usual arrangement of primary and secondary coils. It will be understood that when I speak of a rotatable armature in the description or in the-claims, I mean either an armature that rotates continuously in the same direction or one that oscillates. The low-tension primary coil is shown at P and the high-tension secondary coil at- S in Figs. 1 and 3. The armature A has an end plate or disk 15 at the drive end and an end plate or disk 16 at the other end, these plates being of non-magnetic material. These end plates, which are preferably of bronze or brass, are rigidly secured to the iron poles 17 of the armature core in any suitable way.

The end disk 15 has a hub 18 to which is secured the shaft 19 adapted to be driven from the engine either dire-ct or through a suitable oscillator or impulse starter. This will be clear to those who are acquainted with apparatus of this kind. The shaft 19, which may be called the drive shaft, is rotatably supported in the casting C, through a suitable bearing which, in the present instance, comprises an innerring 20, an outer ring 21 and ball bearings 22. The ring 91 The end piece 3 has a circular is secured in the recess formed by the cylindrical flange or shoulder 13 of the casting C. The bearing 20-21-22 is such as to permit the ready Withdrawal and insertion of the armature in the magneto housing. To the outer face of the end disk 15 is secured a low-tension collector ring, indicated as a whole by L in Figs. and 6. This ring, which is preferably made from a cut-punching of a suitable conducting material, consists of a disk or body portion 23 and a cylindrical contact flange The collector ring L is secured to the end plate or disk of the armature by suitable fastening de vices, such as the screws and 26, as shown in F 4, and is electr'cally insulated from the disk 15 and the grounded framework of the magneto. In the present instance, this insulation is arcomplished as follows, reference being had to Figs. 1 and 3: A ring 27 of suitable insulating material is interposed between the collector ring L and the end disk 15 of the armature. Preferably, the ring or Washer 22' is attached to the ring L by rivets 28 or otherwise, these rivets passing through openings 29 (see Fig. in the disk 23 of the collector ring L. The screw passes through an opening 30 (see Fig. 6) in the collector ring L and is insulated from this ring by an insulating bushing 3]., as clearly shown in 3 and 4. The screw 26, which passes through a hole 132 (see Fig. 6) in the collector ring L, is in electrical contact with the collector ring, but is insulated from the end disk 15 by an insulating bushing 33, as illustrated in Fig. 3. The screw 26 serves as a connecting terminal for the conductor 34, which is connected to :1 common terminal of the armature coils I. and S, as will be understood by those ll d in the art. The end of the conductor rigidly clamped to the screw 26 in any suitable way, as by a nut or otherwise. The conductor 34 ffOI'HiS a common lead from the primer and secondary coils. The other terminal of the primary or low-extension coil P is connected to the metal of the armature and is therefore grounded, as it is techni cally termed.

will be evident that the mounting of the low-tension collector ring L on the end i 15 of the armature saves end space on the tgneto, thereby contributing to the compactness of the machine. Also, a collector ring made from a cut punching is ma; teriall cheaper han the cast or molded slip-rings used in prior machines and which. were mounted directly on the armature shaft, thereby adding tn the length of the magneto.

The opposite end of the armature-the end which I may call the distributor endis supported in an end plate 36 secured to the end piece 3 of casting C by screws or other wise, not necessary to show. A suitable bearing, indicated as a whole by B, rotatably supports the distributor end of the armature in the end plate 86. The bearing B is preferably similar to the bearing 2021-22 which supports the drive end of the rotary armature shaft. In the hub 37 of the end disk 16 is mounted a shaft 39 of suitable insulating material. The inner end of the insulated shaft 39 has a disk-like enlargement 40 which is firmly seated in a correspondingly shaped recess 41 in the end member 1-6 of the armature. Through an axial opening in the shaft 39 extends the leading-out wire 42 of the high-tension secondary coil The wire 42 terminates in or contacts with a button or bushing 44, which is substantially flush with the outer end of shaft 39. 2

Speaking in a practical way, it may be said that the armature shaft of my new magts of the driving end 19 and the i c...tributor end these ends being arranged in axial alignment and constituting in effect a single rotary shaft. The complete embedding of the high-tension conductor 42 between the secondary coil and the button 44 in an insulated portion of the rotary armature shaft removes the danger to which exposed conductors are usually subject in devices of this kind. Furthermore, since the contact button 44 is concentric with the axis of the rotation of the armature, it is practically a stationary contact and requires simpler mechanism for collecting the current therefrom than in the ease of collector ring contacts. The armature as above described may be removed as aunit from the casting or frame 0 after the end plate 36 has been taken off.

I will now describe the primary brush construction, by means of which the lowtension current is collected from the rotary armature. In the top 4 of the casting O is mounted a pair of brushes 46 and 47, made of a good conducting material possessing inherent lubricating qualities and a low contact oropsuch as copper-graphite. The angle at which these brushes are preferably mounted is such that the center line or axis of each brush passes through the axis of the armature shaft, or as nearly so as mechanical conditions permit. This angular arrangement of the brushes is clearly seen in Fig. 4. The brush 46 is arranged to bear upon the flange 24 of the collector ring L as illustrated in Fig. 5, and is completely insulated from the framework of the machine by an insulating bushing 48 lining an opening 49 in the top 4 of casting C. The insulating bushing 48 has a flange 5O adapted to lit into the recess 51 which surrounds the top of the opening 49. The brush 47 passes through an opening 52 in the top 4 of the casting C and is arranged in alignment with the grounded disk 15, which is one of the 0 material.

end members of the armature, as previously described. The brush 4:7 is not insulated from the framework of the machine. The brushes s6 and 47 are pressed against their respective rotary members L and 15 by asingle torsional spring 53 about a pin 5a which may conveniently be in the form of a screw fastened into a projection 55 on the top 4 of the casting C, as best shown in Fig. 5. The hooked or looped end 56 of spring 53 presses down on the brush 46, while the other looped end 57 of the spring bears down on the brush 47, as clearly shown in Fig. 5. An insulating washer or bushing 58 is interposed between the brush 16 and the end 56 ofthe torsional spring 53. The washer 58 is preferably provided with a collar 59 around which the end 56 of the spring. is coiled. This insures the electrical insulation of the brush 46 and at the same time prevents displacement of the spring end 56. The insulating bushing 58-59 may be formed as an integral part from fiber or other suitable insulating The other end 57 of the spring 53 is looped around the conductor 60, which is connected to the brush 47. As the brush 47 is grounded, there is no necessity for interposing any insulation between the brush and the spring. The normal set of the coiled torsional spring 53 is such that it holds the brushes yieldably against the rotary members L and 15, respectively.

Through the insulating bushing 585$) on top of the brush 46 extends a conductor 61,- the inner end of which secured to the brush in any well known manner. The other end of the conductor 61 is fastened to a metal. clip 62 at the point 68. The clip (32 is secured to the projection 64 on the top 4 of the frame or casting C by means of a screw or otherwise. The clip 02 is insulated by means of a pair of insulating washers 67 and 08 between which the clip is clamped. The conductor 60, which leads from the brush 47, is at its other end connected to a metal clip 69 secured to the top of the casting by a screw 7 O passing into an opening 71 in the projection 55 on top of the casting C.

The top 4 of casting C is provided with a recess or chamber 72 for receiving a condenser K of suitable construction. The condenser chamber 72 is covered by a plate 73, which is held in place by the screw 7 0 and additional screws 74 and 75, or by any other suitable means. As shown in Fig. 2, the plate 7 3 does not entirely cover the condenser chamber but leaves a space sufficient to bring out the insulated condenser terminal 76. The plate 73 has the advanthat it keeps the condenser compressed, thus insuring a practically constant capacity. To the terminal 7 6 are connected the conductors 7 7 and 78, while the other terminal of the condenser is grounded under screw 74, these condenser connections being well understood by those familiar with ignition apparatus. The conductor '77 is electrically connected to the insulated clip 62, to which the brush 4.6 is connected, as pre viously described. The conductor 78 is suitably connected to a fixed terminal 80 at the point 81. The terminal 80 is a block of good conducting material supported on a rigid insulating strip 82 and carrying an adjustable contact screw 87, which cooperates with a movable contact 88 to form the circuit breaker of the magneto for controlling the primary circuit, as will be understood by those skilled in thi art. It will not be necessary to describe the structural details of the mounting for the movable contact 88, since that forms no part of my present invention. For the details of such mounting, reference may be had to my copending application, Serial Number 50%,- 934, filed October 3, 1921, of which the present application is a division. It is enough to say here that the movable contact 88 is controlled by a cam disk R secured to the end plate 16 of the armature.

By mounting the primary brushes 46 and 4.7, the condenser K and the breaker contacts 87 and 89, all on top of the magneto frame C, they are in an easily accessible position and may thus be readily replaced or inspected when desired. This is an advantage, because .it is well known that these parts are liable to get out of order. To protect the parts referred to against dust and moisture, I provide a cover 104 which fits tightly on top of the casting and is secured in place by suitable means, such as screws 105 or bails. The lower edge of cover 10 1 closely surrounds the flange or shoulder 100 formed on the top of the casting. In this way the cover is easily centered on the cast ing and. fits snugly in place, producing practically a dust proof and moisture-proof casing for the brushes, the condenser and the circuit breaker.

In a single-cylinder magnetothat is to say, a magneto connected to a single-cylinder engine the distributor through which the current is led to the spark plug need have but a single contact. Such a distributor is shown in Figs. 1, 2 and This distributor consists of a properly shaped block 107 of insulating material provided with a chamber 108, into which projects a brush or contact 109. This brush is usually a piece of carbon and is mounted in a hollow metal plug 110 embedded in the block 107, as best shown in Fig. 1. A light spring 111 presses the brush 109 against the contact 44 when the block 107 is in place on the magneto. A cable or conductor 112, encased in suitable insulation 113, is electrically connected to the metal plug 110. The cable 112 passes through an opening 114 in the distrilnitor block lo? and the frayed ends 115 of the wires which constitute the conductor 112 are pushed ti ilt against the metal plug (see Fig. 1), thereby producing a firm electrical connection between the collector brus'l. 109 and the cable 112, which leads to the insulated terminal of a spark plug. The distributor blocl: is held in place on the magneto by any suitable means, such as a spring arm 122 pivoted on the stud 123 carried by the end plate 36. l i hen the s ing arm 122 is in locking position, it on s the block 107 substantially at the center, as shown in Figs. 2 and 3. To release the distributor block it only necessary to swing the arn' 122 out of contact with the blocir.

It will be understood that I have shown a distributor for a single-cylinder engine by way of illustration and for the sake of simplicity, and it is obvious that my new magneto is applicable to n'nilti-cylinder e11- gines by simply attaching an appropriate distributor in place of the block 107. I have explained this fully in my aforesaid copending application.

This application is filed as a division of my aforesaid copending application, because of an oflicial requirement of division made in the parent case.

lVhile I have herein shown and described a specific construction, I do not intend to be limited to the details set forth. It is obvious that changes and modifications may be resorted to and yet be within the scope of my invention as defined in the appended claims. 1

What I claim as my invention is:

1. In an ignition magneto, a non-magnetic frame in which the armature is mounted, said frame having a top provided with a pair of openings arranged at an angle to each other and approximately radial with respect to the axis of the armature, said openings being relatively displaced longitu dinally of the frame, means for insulating one of said openings, a brush slidably mounted in said insulated opening, a grounded brush slidably mounted in the other opening, an insulated collector ring and a grounded disk rotatably mounted within said frame in position to be engaged respectively by said insulated brush and said grounded brush, a coil spring mounted means on top of said frame having oppositely extending arms yieldably pressing said brushes against said ring and said disk respectively, and circuit connections for said brushes.

2. In an ignition magneto, a non-magnetic frame in which the armature is mounted, said frame having a top provided with a pair of openings arranged approximately radial with respect to the axis of the armature, said openings being relatively displaced longitudinally of the frame, means for insulating one of said openings, a brush slidably mounted in said insulated opening, a grounded brush slidably mounted in the other opening, an insulated collector ring and a grounded disk rotatably mounted within said frame in position to be engaged respectively by said insulated brush and said grounded brush, a single torsion spring mounted on top of said frame and having its opposite ends engaging said brushes so as to hold them in contact with said ring and disk respectively, means for insulating said spring from said insulated brush, and circuit connections for said brushes.

25. in an ignition magneto, a non-magnetic frame having a pair of openings in the top thereof, an insulated brush in one opening, a grounded brush in the other opening, said brushes projecting through the top of the frame, a single spring mounted on top of the frame and having oppositely extended ends which engage the projecting ends of said brushes to press the brushes inwardly and means for insulating said spring from said insulated brush.

l. In an ignition magneto, a non-magnetic frame in which the armature is mounted, a

pair of current-carrying members rotatable with said armature and insulated from each other, a pair of brushes mounted in openings in the top of said frame and projecting through said top, one of said brushes being insulated from the frame and the other brush being grounded, a conductor connected to the projecting end of each brush, a spring mounted on top of said frame and having oppositely extending ends arranged to bear down on said brushes and thereby hold them in contact with said members, each end of said spring terminating in a hook or loop which passes around the conductor of the associated brush, whereby said spring ends are locked against accidental displacement, and means for insulating said insulated brush from said spring.

5. In an ignition magneto, a non-magnetic frame in which the armature is mounted, a pair of current-carrying members rotatable with said armature and insulated from each other, a pair of brushes mounted in openings in the top of said frame and projecting through said top, one of said brushes being insulated from the =e and the other brush being grounded, a conductor connected to the projecting end of each brush, an insulating washer on top of said insulated brush, said washer having a collar through which the connected conductor passes, a spring mounted on top of said frame and having oppositely extended ends which terminate each in a hook or loop, one of said looped ends passing around the collar of said washer and the other looped end passing around the conductor of the other brush,

whereby said spring ends are locked against displacement, the normal tension of said spring being such that its ends exert a' clownward pressure on said brushes to hold them in contact with said currentcarrying memhers.

6. In an ignition magneto, a non-magnetic frame in which the armature is rotatably mounted, an insulated collector ring rotatable with said armature, the top of said frame having an opening, an insulating bushing in said opening, a brush slidaloly mounted in said bushing and arranged to contact With said collector ring, said brush projecting through the top of said frame, a conductor connected to the projecting end of said brush for establishing the required circuit connection, an insulating washer on top of said brush, said conductor passing through said washer, a projecting pin fixed on the top of said frame, and a wire spring. coiled on said pin and having an arm with a looped end surrounding said conductor and bearing down on said washer, whereby said spring is insulated from said brush and locked thereto against accidental displacement, the

tension of said spring holding the brush in contact with the collector ring.

7. In an ignition magneto, a non-magnetic frame in which the armature is rotatably mounted, an insulated collector ring rotatahle with said armature, the top of said frame having an opening, an insulating bushing in said opening, a brush slidaloly mounted in said bushing and arranged to contact with said collector ring, said brush projecting through the top of said frame, a conductor connected to the projecting end of said brush for establishing the required circuit connection, an insulating washer on top of said brush, said washer having a collar through which said conductor passes, a projecting pin fixed on the top of said frame, and a wire spring coiled on said pin and having an arm with a looped end surrounding said collar and bearing down on said washer, whereby said spring is insulated from said brush and locked thereto against accidental displacement, the tension of said spring holding the brush in contact with the collector ring.

FREDERICK W. ANDREW, 

